Numerous types of trigger mechanisms for fluid dispensers exist in the art. These triggers are usually operated by a single hand. Such triggers are in use on fuel pump nozzles, on hand actuated pump sprayers, and on hand actuated pressurized sprayers such as the common pressure washer to name a few. These fluid dispensers sometimes are releasing fluid that is contained in a pressurized storage device or supplied under pressure by a pump or supplied from a gravity fed system. The art of trigger design for such fluid dispensing devices is characterized by a single axis trigger which when actuated by the hand of the operator rotates in a single plane about the aforementioned axis by an inward pivot toward the handle and an outward pivot away from the handle. When the operator holds the dispenser by the handle and applies a force to the trigger causing the inward pivot toward the handle, a valve mechanism in the fluid dispenser is engaged and the pressurized fluid is released. When the operator ceases the application of the force to the trigger, a return mechanism causes the trigger to return to its initial resting position at the end of the outward pivot away from the handle and the valve mechanism ceases to be engaged and is closed by its own return mechanism or by the force of the fluid pressure or by both.
These single axis triggers have been known in the art for a long time and have been improved over the years by the addition of various ergonomic or styled grip designs and locking mechanisms, all with the intent to relieve some of the stress created by the high force demands on the hand of the operator. A relatively high user engagement force has been required to overcome the force of the return mechanism and friction. In particular, the trigger return mechanism force must be high to assure that the trigger lever returns to the fully open position, which position results in the valve being closed when the trigger is released. High force demands placed on the hand can cause discomfort, fatigue, and musculoskeletal disorders. Unfortunately, though some improvements have been made as noted above, these hand-stress disorders (resulting from repeated trigger operation, continuous trigger hold down, or a mixture of both during ordinary use of fluid dispensing triggers) remain a critical problem in the art. Thus, it is desirable to provide an improved trigger lever that can actuate the fluid dispenser and reduce the amount of hand-stress the operator experiences. It is in this light that the present invention seeks to relieve stress on the hand through implementation of an improved force transmission device.